Callaghnite, Gabbs, Nevada 2.0mm field, (Nikon U10 objective)
Greenockite, Siglo XX Mine, Llallagua, Bolivia 2.3mm field, (Nikon U10 objective)
Gunterblassite, Rother Kopf, Eifel, Germany 1.0mm field, (Nikon U20 objective)
Marko uses an Olympus E-330 with an Olympus bellows. He uses either lenses with an Olympus OM Mount or a RMS thread adapter to mount microscope objectives. He has a translation stage which permits micron resolution motion. He uses the micrometer to move the stage by hand in order to do focus stacking.
The Olympus E-330 is a digital SLR with a 7.5 megapixel sensor in the Four Thirds system format. It was released in 2006 and was the first DSLR to have a live preview feature, which is ideally suited to macro photography. It also has an ultrasonic vibrator dust elimination system. The crop factor for a 4/3 sensor is about 2. The imaging area of the sensor is about 17.3 by 13mm. (Micro 4/3 cameras use the same size sensor, but do not have a reflex mirror or pentaprism - allowing a very thin camera body.)
He used to use LED's for illumination, and the photos of his apparatus show him using a Medusa3000 LED light source, which had a color temperature of about 7800K. He says that he tried other daylight color LED illuminators, but found that red and green colors were not true. (Other people, such as Joy Desor are able to obtain good results with cheap LEDs). He now uses a cold light mirror lamp (Schott KL 1500). The KL 1500 is based on a 15 volt, 150 Watt halogen incandescent bulb and illuminates a fiber bundle.
Marko says he always uses diffusors (which makes good sense). You can see one in use (a small piece of paper attached to the microscope objective he is using) in the photos of his apparatus. He now uses a tube made from white plastic sheet from a craft store. He says that without a diffusor the reflections ruin the picture and often the photos are less sharp.
Here are some photos of his setup:
His arsenal of lenses is:
the U10 and U20 are objectives from metallographic microscopes and have a built in iris to allow control of depth of field. The U10 has an NA of 0.22 and a 16mm focal length. The U20 has a 8mm focal length and an NA of 0.33.
The Olympus lenses are OM mount macro bellows lens. The 38mm is an f/3.5 lens. The 80mm is an f/4.0 lens.
Tom's Mineralogy Info / firstname.lastname@example.org